1. The Field of the Invention
The present invention relates to methods and systems for booting computers over a network using an operating system stored on a server. In particular, the present invention relates to methods and systems for booting computers over a network regardless of changes in the hardware configuration of the computers since the last time the computers were connected to the server.
2. The Prior State of the Art
As computers have become more powerful and less expensive, their acceptance and use in business have continually increased over the years, and are now standard in many industries. The increasing use of computer networks has been a significant factor in employee productivity gains in the economy. Because the price of computers has generally decreased over the years, the purchase price of a computer is now often a relatively small percentage of the total cost of owning and operating a computer in the business setting. Increasingly, from a business standpoint, the total cost of ownership is a significant factor in the number of computers owned by a business and the breadth of activities in which computers are used. Frequently, a major portion of the total cost of ownership includes installation of new computers and new hardware, the cost of software, and general network administration.
Sometimes, as a result of software problems or hardware failure, a client computer may be rendered temporarily or permanently unusable. For example, the hard disk or the motherboard of a client computer is subject to the risk of failure, with the result that the failed hardware must be replaced or an entirely new computer must be substituted for the failed device. The cost of computer failure includes not only the cost of purchasing new hardware or a new computer but also the time required to physically connect the computer to the network and to configure the computer and the server in order to boot the new computer and make it available to a user. Furthermore, a significant amount of time and cost may be spent in reinstalling and configuring programs that had been used on the particular failed computer.
An example of a typical computer network in the prior art is illustrated in FIG. 1. Network 10 includes one or more server computers 12, one or more client computers 14, and a network infrastructure 16 that allows information to pass between the server computers and the client computers. If a computer 14 fails, it is likely that the hardware of a replacement computer is different from the hardware of the failed computer. If so, the operating system as previously configured may be incompatible with the new hardware. As a result, the administrator is ordinarily required to install the proper operating system software or device drivers in order to support the replacement computer. The administrator time spent in configuring the replacement client computer combined with the down time and associated loss in employee productivity from lack of access to the computer significantly contributes to the total cost of owning a computer in the business setting.
The cost and inconvenience of replacing a failed computer or failed hardware is particularly great when the failed hardware is the hard disk. Failure of a hard disk in a network setting such as that illustrated in FIG. 1 may involve the loss of a great deal of potentially valuable information. Furthermore, the cost of the lost data generally includes the employee time required to replace the data.
Certain types of hardware components are increasingly automatically installed and supported by operating systems and associated device drivers. For example, printers, sound cards, video cards and the like may be essentially automatically installed and supported by some operating systems with minimal or no user input. For instance, some operating systems automatically recognize the presence of changed hardware after the operating system boots on the computer and then update or install device drivers accordingly.
The foregoing method of automatically supporting new hardware has previously been inapplicable to hardware that operates during bootup and initial execution of the operating system software. Unless the changed hardware has already been recognized and the operating system software updated accordingly, the computer is unable to boot in the first place. However, without first booting the operating system, the presence and identity of the new hardware components cannot be detected. Thus, in the past, the foregoing two requirements have been mutually exclusive, and new hardware used during the bootup process has been incompatible with methods of automatic hardware recognition and automatic configuration of the operating system. As a result, when a hard drive or a motherboard, for example, is replaced with new hardware, the user has been required to manually reconfigure the operating system. The foregoing problem has been a significant hindrance in the otherwise successful effort of minimizing administrative attention needed to replace networked computers and update hardware.
In view of the foregoing, it would be a great advancement in the art to provide a system for automatically adjusting operating system software for new hardware components, particularly those that must operate during the booting process. Furthermore, it would be a great advantage to provide network systems wherein a replacement computer or replacement hardware may be installed and automatically supported by the servers with minimal or no user or administrator attention. It would be particularly advantageous if such methods would allow a replacement computer or replacement hard disk to automatically obtain the data stored on a previous or failed computer or hard disk. Such methods and systems would significantly reduce the total cost of ownership of computers in the business setting and would reduce the administrative costs of operating computer networks.